Respiratory Symptoms and Wheat Flour Exposure: A Study of Flour Millers

Abstract

The objective of this study was to determine the prevalence of respiratory symptoms and their relationship to sensitization to wheat flour allergens and fungal amylase, in a group of workers from the UK flour milling industry. A cross-sectional study was used to evaluate symptoms, using a structured interview technique, and sensitization, using skin prick test findings, from 679 employees in flour milling and packing operations at 18 flour mills. A total of 147 workers (147/679, 22%) described upper respiratory tract symptoms of some kind. In the majority (139/147, 95%) these symptoms were of an occasional or transitory nature and were related to short-term exposures to high levels of dust. Three individuals (3/679, 0.4%) were identified whose symptoms were thought to be the result of allergy to wheat flour. The prevalence of positive skin prick tests to wheat flour allergens and to fungal amylase was 1.2% (8/678) and 0.9% (6/678), respectively. Measurements of total inhalable dust exposure for personnel exposed to flour dust were taken at 10 of the sites (116 samples). For production personnel the levels were typically between 1 and 10 mg/m3 (8-h time weighted average), with a median of 6.2 mg/m3. Hygiene operatives had appreciably higher exposure than production personnel, with a median of 18.7 mg/m3. Overall, 43% (50/116) of all samples exceeded 10 mg/m3 (8-h time weighted average). The findings suggest that the risk of sensitization to wheat flour allergens from current dust exposures in flour mills is very low. Wheat allergy was responsible in only a small proportion of the total who had respiratory symptoms. The principal causation of symptoms experienced by the workforce was considered to be a non-specific irritant effect related to short-term exposures to high levels of total inhalable dust.

Pulmonary function impairment and airway allergy among workers in traditional bakeries

“…Positive SPT to wheat grain was more prevalent among bakers compared to the control group with statistically significant difference. This is in accordance with many authors, who reported that the principal sensitizer in bread bakeries is wheat flour dust [2,3,[18][19][20][21][22]. [27] investigated pulmonary function parameters in non-smoking bakery workers and reported that the exposed group had lower forced expiratory indices than the control group.…”

Pharmacological Studies of the Effect of Wheat Grain Extract

“…This response was characterized by activation of neutrophils and fibroblasts. Similarly, Smith et al [23]described that respiratory symptoms following wheat flour exposure are due to nonspecific irritant effects. DoPico et al [24]performed inhalation provocation tests with extracts of durum wheat and durum wheat airborne dust in grain elevator workers and found 20% decrements of FEV 1 .…”

Prevalence of respiratory symptoms among wheat flour mill workers in Ibadan, Nigeria

“…In developing countries, relatively large numbers of people are employed in industries processing agricultural products, and this has made the problem of exposure to vegetable dusts (grain, cotton, tobacco, tea) more serious there [WHO, 1993]. Crosssectional epidemiological studies have shown a higher prevalence of respiratory symptoms among grain handlers compared with workers not so exposed, even after controlling for the effect of smoking [Bachmann and Myers, 1991;Laraqui et al, 2000;Smith et al, 2000;Viet et al, 2001]. Among related substances, wheat dust has been most frequently implicated as an allergen for allergic rhinitis and work related asthma in cereal flour workers [Prichard et al, 1994].…”